Thiocarbonates of aromatic polyhydroxy compounds



Patented Oct. 19, 1943 UNITED STATES PAT THIOGARBONATES F AROMAT-iC POLY- HYDROXY COMPOUNDS I Georg Werner, Wiesbaderi-Biiabrich, ,QGermany,

assignor, by mesne assignments, to Winthrop Chemical Company, Inc.', New York, N. Y., a corporation of New York 'No Drawing. Application September 7, 1940, Se-

rial No. 355,809. In Germany March 29, 1938 6 Claims.

whereinR stands for a benzene or naphthalene nucleus, the heterocyclic ring being bound to the aromatic nucleus in 1.2-position.

In my copending application serial No. 263,903 I have shown that the imino-thio-carbonate of aromatic poly-hydroxy compounds which correspond to the formula wherein R has the samelmeaning'as mentioned above may be obtained by causing an agent yielding thiocyanogen to act" upon an aromatic polyhydroxy compound containing, with respect to one of the hydroxyl 'groups, a free ortho-position' preferred for substitution and neutralizating the thiocyanic acid formed during the reaction. Suitable poly-hydroxy compounds are poly-hydroxy compounds of the benzene and naphthalene series which may be substituted, for instance, by halogen atoms for instance chlorine or bromine or by alkyl or aryl radicals, such as-resorcinol, cresorcinol, orcinol, phloroglucinoL- dihydroxynaphthalenes and the-like. 'Ihe poly-hydro'xy compounds may also. contain as substituents etherified hydroxy groups such as alkoxy groups. Thus, there may be used as parent material, for instance 1.3-hydroxy--ethoxybenzene, 1.3-dihydroxy-fi-methoxybenzene or 1.4-dihydroxy-5- methoxybenzene, provided that these compounds contain, with respect to one hydroxyl group, a free ortho-position preferred for substitution. 2.

I Now it has been found that theuthiocarbonates free from nitrogen may beobtained by heatingthe solutions of the imino-compounds described in my copending application'Serial No. 263,903 in aqueous mineral acids. In general a short heating of the hydrochloric acid solutions or the sulfuric acid solutions is suflicient. Many iminothio-carbonates already decompose in the" cold when they stand for a prolonged time in .mineral acid solution. .In most-cases it.is,-however, prefarable to;boil :the acid solutionsof th zimino' compoundsfor about 10 minutes. The concentration of the imino-thiocarbonates in these solutions may amount to about 515%.' The thiocarbonates of polyhydroxy compounds of the benzene or naphthalene series obtained in this manner constitute well crystallized new. products which are, for instance, verysuitable for being used as a'zo components in the production of azo.

dyestuffs. Moreover they may be employed as disinfecting means. Furthermore the new compounds are very suitable intermediate products in the manufacture of medicines and particularly dyestuffsv as illustrated in the followin examples.

The examples serve to illustrate the invention, I

but they are not intended to limit it thereto:

Example 1.-40 grams of potassium thiocyanate in 50 cc. of water are added, While stirring at room temperature, to a solution of 11 grams of resorcinol and 50 grams of crystallized copper The black cu'plic sulfate in 250 cc. of water. thiocyanate formed becomes colorless after a short time, which indicates that the introduction of thiocyanogen is terminated. The cuprous thiocyanate is removed by filtering with suction and then washed with water; the filtrate is mixed with 50 cc. of a 2n-sodium carbonate solution, whereby the imino-thiocarbonate of resorcinol C=NH V separates in the form of a colorless crystalline body. The yield amounts to 16 grams. The new compound which melts at 149 C. dissolves very easily in many organic solvents and in mineral acids. It forms Well defined salts;

A 10% solution of the imino-thiocarbonate of resorcinol-in 10% hydrochloric acid is heated for 15 minutes on'thesteam bath. The thioc'arbonate free from nitrogen, which corresponds to the formula:

. oo' .1 I

separates, on cooling, in theform of fine crystals melting at 158 C. 3 v

This thiocarbonate may easily be saponified with alkali so as to form 2.4-dihydroxy-phenylsulfide. This compound may be alkylated, for instance, with dimethyl sulfate, so a to form 2.4 dihydroxy 1 alkyl mer'capto benzene. The latter compound is a well suitable azo component for the produ'ctionof azo dyestuffs.

ENT OFFICE Example 2.-5O grams of crystallized copper sulfate in 100 cc. of water are added, while stirring at room temperature, to a solution of 16.2 grams of crystallized phloroglucinol and 36 grams of sodium thiocyanate of 90% strength, in 100 cc. of water. The cupric thiocyanate which i first formed becomes nearly instantaneously colorless, which proves that the thiocyanation' has occurred very quickly. The solutionlis freed from the cuprous thiocyanate and the thiocyanic acid is neutralized by means of a 2n-so'diurn carbonate solution; the imino-th iocarbonate of phloroglucinol thereby separates. Any excess of sodium carbonate should be avoided, since it would again bring about dissolution. The new product, thus obtained, dissolves 'very' easily in'dilute acids; its hydrochloride forms very well defined crystals.

The imino-thiocarbonate of phloroglucinol is transformed in the sulfuric acid salt. The" aqueous solution of this salt is heated for'a' short time, for example, for half an houron th'e'steam bath. The im'ino radical is then'split off, and

the thiocarbonate free from nitrogen which'c'orresponds to the following" formula:

crystallizes, on cooling, in the form of long ;nee,-.

dles, melting at 181 C- Example 3.-16; grams of ,2.3 -'dihydroxy-naphthalene are dissolved in 100 cc. of alcohol and mixed, while stirring, with 40. grams, of cupric thiocyanate. Assoon asall of the cupricsalt has been transformed into the cuprous salt, the reaction mixture is filtered and the imino-thiocarbonate of 2.3-dihydroxy-naphthalene cipitates after a short time; it melts at 199 C. It corresponds to the formula:

The same reaction maybe carriedout; for-in-i.

' Y the formula:

stance, with 2.7-dihydroxy-naphthalene, whereby a product of the formula:

is obtained.

Example -4.-12;4 grams of anhydrous orcinol and 40 grams 0f cupric thiocyanate are stirred together iii-Z0 'cc. of methanol. As soon as the mixturehas completely decolorized, the cuprous thiocyanate is filtered with suction; by addition of 50 cc.-of 2n-sodium carbonate solution to the filtrate, the imino-thiocarbonate of orcionol HO- /O is precipitated, recrystallized from alcohol, the product melts after first becoming brown at 174 C.-1'I5 C.

The imino-thiocarbonate of orcinol is hydrolyzed by means of hydrochloric acid in the mannerdescribed inExample 1. The thiocarbonate obtainedmeltsat 140 C. It corresponds to the formula:

Example 5.-14.5 grams of l-chloro-2A-dihydroxy-benzene and 50 grams of crystallized copper-sulfate are'idisso1vedin:250 ccuof water, and 4owgrams-ofipotassium thiocyanate Lin 5000. of water are then' added,while stirring. Decoloration immediately 1 sets in. The :imino-thiocarboname i of Lchloro-ZA dihydroxybenzene melts at 172 C.

.A -5%=-solution of .:the.imino-.thiocarbonate of 1--ch10ro2.4-dihydroxybenzene in :10.% :hydrochloric acid is heated' for half an hour on the steam bath. 0n cooling,-the thiocarbonateof separates. -It melts at 159 C. .olnenanalogous manner, the thiocarbona'te' of; I-brommZA-adihydroxy-benzene.

can be :obtained from 1 bromo-'2.4'-wdihydroxybenzene. A

Example" til-42.4 grams o 2.6-dihydroxy-tolueneare dissolved in :cc. of alcohol of 50% C=NH is precipitated by addition to the filtrate of dilute sodium carbonate solution. By hydrolyzing this compound in the manner described in Example 1, a thiocarbonate of the formula:

is obtained.

1 HO\ /O I claim:

1. As a new product, a substance of the following general formula:

wherein R stands for an aromatic nucleus selected from the group consisting of the benzene nucleus and the naphthalene nucleus, which nucleus R carries at least one substituent, namely a hydroxyl group, the heterocyclic ring being bound to the aromatic nucleus in 1.2-position.

2. As a new product, a substance of the following general formula:

wherein R stands for an aromatic nucleus selected from the group consisting of the benzene nucleus and the naphthalene nucleus, which nucleus R carries at least one hydroxyl group as substituent, the further positions of B being occupied by substituents select-ed from the group 5 consisting of hydrogen, methyl, hydroxy, methoxy, ethoxy, chlorine and bromine, the hetero- I cyclic ring being bound to the aromatic nucleus in 1.2-position.

3. As a new'product, a substance of the following general formula: 0 R\ 00 s wherein R stands for a benzene nucleus which carries a hydroxyl group as substituent in paraposition to the sulfur atom, the further positions of R being occupied by substituents selected from the group consisting of hydrogen, methyl, hydroxy, methoxy, ethoxy, chlorine and bromine, the heterocyclic ring being bound to the benzene nucleus in 1.2-position.

4. As a new product, a substance of the following formula 5. As a new product, a substance of th following formula HO O H0\ 0 {I 01 s GEORG WERNER. 

